FORTY UNDER 40;ETHER ORE

Adam and Eric Heneghan have vaulted from the fringes of cyberculture to the forefront of the hottest trend in advertising.

Last year, the brothers linked their digital design company with Leo Burnett, the Chicago-based advertising agency with 62 offices around the world and 1994 billings of $4.6 billion, in an exclusive alliance to create interactive advertising.

They were assigned to work with Rishad Tobaccowala, a 13-year Burnett veteran who left a comfortable position as an account director to head the agency's foray into the wilds of cyberspace.

On the surface, the plan seemed simple: Combine the Heneghans' programming talents with Mr. Tobaccowala's marketing acumen to test the potential of interactive advertising. But it soon became clear that the job required them to change the way their colleagues and clients think about advertising.

"It's an un-education process," says Adam Heneghan.

Their radical message is that communication runs both ways in the interactive age, and that advertisers who don't let consumers have their say will be left in the ether.

Among their most successful efforts is an on-line forum for Oldsmobile that allows consumers to ask questions and even complain about the cars. An interactive CD-ROM they designed for the Sony Magic Link personal digital assistant demonstrates the features of the product in response to viewer commands.

Mr. Tobaccowala describes the effort to redefine advertising in both epochal and prosaic terms.

"We approach this as potentially the fourth communications revolution," he says. But in the next breath, he calls the new media "another channel to help build brands."

Rob Nolan, Burnett's vice-chairman and director of creative services, professes great faith in Mr. Tobaccowala's vision. "He's in the 21st century when it comes to technology."

The thousands of on-line visitors accessing the ad forums created by the trio have convinced Eric Heneghan that the group is hitting its target.

"We've created things that are new and innovative," he says, "and we've been able to do it in a profitable way."